Dynamic routing of transit vehicles

ABSTRACT

Systems and techniques are described to enable the dynamic selection of a transit route through the stop zones of a transit line. Techniques are disclosed for receiving a current location of a transit vehicle on a transit line and determining a transit route through one or more of the vehicle&#39;s remaining stop zones by choosing an optimized combination of stop options and route segment options for that specific transit vehicle. Techniques may be performed in some cases by accessing a real-time traffic information service to obtain one or more traffic condition factors on a route segment, determining a dynamic route segment option weight, calculating a dynamic cost function with respect to the weights, and determining an optimized set of the route segments with respect to the cost functions.

GOVERNMENT SUPPORT

This invention was made with government support under grant numberIIS-1213026 awarded by the National Science Foundation. The governmenthas certain rights in the invention.

BACKGROUND

Generally, a transit system is a large-scale public transportationsystem serving a given area, typically comprising buses, subways, andelevated trains. A transit system usually has numerous transit lineswhich represent pathways through the given area from a starting point toan ending point through various intermediate stopping points. One ormore transit vehicles can service a particular transit line, generallyseveral times a day.

Express transit lines, for example the transit lines serviced by expresstransit vehicles like express buses, sometimes consist of relatively fewstops connected by route segments of significant length. Heavy traffic,lane blockages due to accidents, weather, and other factors can allaffect the punctuality and reliability of these express transitvehicles. Despite the availability of current traffic information,generally express transit vehicles follow a fixed path irrespective oftraffic conditions, and so riders of express transit vehicles must dealwith low reliability/punctuality, and even cancelled trips, in responseto conditions that cause longer delays.

BRIEF SUMMARY

Systems and techniques are described to enable the dynamic selection ofa transit route through the stop zones of a transit line. The disclosedtechniques and systems improve the reliability, punctuality, and levelof service of transit vehicles by utilizing available informationbetter.

Embodiments of the subject invention are disclosed for describing atransit line so that each planned stop has a set of alternative stopoptions, which are connected by sets of route segment options. A plannedstop and its alternative stop options form a “stop zone.” In case ofdelays in the vicinity of a planned stop, embodiments of the subjectinvention can select a local alternative stop which can be reached moreeasily and can also notify prospective passengers waiting at the stopand passengers already aboard the vehicle.

Embodiments of the subject invention select the most advantageous routesegment options by interacting with real-time traffic informationsystems to obtain an understanding of current and predicted trafficconditions. Thus, transit vehicles do not follow the same route duringthe execution of every scheduled trip, but can be rerouted in accordancewith real-time and predictive traffic data and other dynamic conditions.

In some embodiments, disclosed systems and techniques can select atransit route that skips one or more stop zones if the stop zones cannotbe reached without massive delay.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example component environment for dynamic selection oftransit routes.

FIG. 2A shows an example of a particular stop zone and associated stopoptions.

FIG. 2B shows an example of a transit line's stop zones, stop options,and route segment options as a directed, acyclic graph.

FIG. 3 shows an example process flow for dynamic selection of transitroutes.

FIG. 4 shows a block diagram illustrating components of a computingdevice or system used in some implementations.

DETAILED DESCRIPTION

Systems and techniques are described to enable the dynamic selection ofa transit route through the stop zones of a transit line.

An embodiment of the subject invention includes techniques for receivinga current location of a transit vehicle on a transit line anddetermining a transit route through one or more of the vehicle'sremaining stop zones by choosing an optimized combination of stopoptions and route segment options for that specific transit vehicle.Embodiments include accessing a real-time traffic information service toobtain one or more traffic condition factors on a route segment,determining a dynamic route segment option weight, calculating a dynamiccost function with respect to the weights, and determining an optimizedset of the route segments with respect to the cost functions.

Certain embodiments of the subject invention include a data store thatstores data, metadata, and properties related to one or more transitline, stop zones within a transit line, stop options for a stop zone,and route segment options between a stop option and a subsequent stopoption. An embodiment further comprises a stop option weighting factorto indicate the relative desirability of a particular stop option inaccordance with one or more preference criteria.

An embodiment of the subject invention further includes techniques fordetermining whether to skip a stop zone altogether; these embodimentsmay use one or more skip weighting factors for the determination.

Technical effects of the technical features of embodiments of thesubject invention can include improving the reliability and punctualityof transit vehicles. Avoiding unnecessary waits in traffic congestioncan save unnecessary energy consumption and in some cases loweremissions and pollution associated with idling transit vehicles.

FIG. 1 shows an example component environment for dynamic selection oftransit routes. Generally, a dispatcher service 100 implementstechniques in order to dynamically select transit routes that areadaptive to real-time conditions, providing transit vehicle drivers witha way to avoid unnecessary delays that needlessly waste energy or createexcess vehicle emissions. In FIG. 1, dispatcher service 100 implementscertain techniques in coordination with other system components.Dispatcher service 100 receives input from transit vehicle locationdevices 110, interacts with real-time traffic information services 120,communicates with notification interface 130 devices that providenotifications to operators and passengers, reads/stores information inthe data store 105, and in some cases interfaces with other components150 to gather information for the selection of transit routes. These andcertain other techniques will be described more fully with respect tothe process flow in FIG. 3.

Dispatcher service 100 may utilize or interact with a data store 105that stores a variety of information relating to the operations of thedispatcher service 100. The data store 105 may contain a data structurefor storing data, metadata, and/or properties relating to one or moretransit lines in a transit system. For each of the transit lines, thedata store may contain a sequence of stop zones served by each transitline in the system. A “stop zone” refers to a geographical area, such asa street, block or collection of streets or blocks, that allows theembarking and disembarking of passengers on or from a transit vehicle.The sequence of “stop zones” in a particular transit line may be denotedin some cases herein as (s₁, s₂, . . . , s_(n)). For stop zones, thedata store may include data, metadata, or properties such as thegeo-location of the stop and one or more planned times of arrival. Insome cases, the planned times of arrival may be distinctly associatedwith any combination of: one or more transit lines, one or more transitroutes, one or more transit vehicles, and/or days of the week or month(e.g., calendar days, days of week, weekdays vs. weekend days,holidays).

A stop zone on a particular transit line has one or more “stop options.”Stop options are different possible places to actually stop in thegeneral locality of the transit line “stop zone.” As an example,consider a normal stop on a given transit line that is located at awell-accommodated and well-covered bus kiosk on a main thoroughfare.This normal stop (or “ordinary stop,” or “regular stop”) is thepreferred stop option on this line because it is well-positioned toprovide the riders access to several office buildings, shopping, and theability to catch a variety of local buses. However, the bus is oftendelayed in arriving at the normal stop option because of lengthy delaysdue to accidents on the busy main thoroughfare. Thus, it may make senseto have at least one alternative “stop option” that is not on the mainthoroughfare but is instead several blocks away on a less-busy street.The alternative stop option can be reached without the lengthy waittimes, and may have similar accoutrements to the normal stop. However,more patrons may be inconvenienced by the distance of the alternativestop from their desired arrival point. Several alternative stop optionsmay be available for each stop zone. Generally, the alternative stopoptions offer sufficiently distinctive access ways to avoid problematicconditions related to the normal stop, but are still close enough toenable passengers to arrive at their destinations in a reasonable timeframe. A stop zone's set of local stop options may be denoted herein asA(s_(i))={s_(i,0), s_(i,1), . . . , s_(i,m(i))}, where the normal stopoption, s_(i)=s_(i,0).

The data store 105 may also include a plurality of “stop optionweighting factors,” each of which is associated with a stop option, anddescribes the relative desirability of the stop option with respect tothe normal stop option and the other alternative stop options. A stopoption weighting factor may be denoted herein as w(s_(i,j)).

The stop option weighting factor can be derived in accordance with avariety of preference criteria which describes the relative desirabilityof the stop option. A stop option weighting factor can have preferencecriteria with a combination of static and dynamic aspects. One type ofstatic aspect can be a base numerical value, such as that the normalstop option weighting factor w(s_(i,0)), is 1.0, for example. Anothertype of static aspect can be the walking distance from the alternativestop option to the normal stop. Another kind of static aspect canquantify the quality of the facilities at the alternative stop (e.g.,signage, shelters, raised sidewalks, disabled access, restrooms, andother amenities). Another category of static aspect could include thequality of available pedestrian access to the alternative stop from thenormal stop.

Dynamic aspects include a quantification of preference criteria thatmight relate to temporary or transient factors. For example, the stopoption weighting factor might vary in accordance with the season ortemperature, e.g., an alternative stop option having a shelter withoutclimate control could have a weighting factor reflecting greaterdesirability in seasonable times of year such as spring or fall than inwinter or summer. Information that may inform a dynamic aspect may beobtained, for example, from weather services, calendar services, orother external information sources.

The stop option weighting factor may be used in techniques implementedby the dispatcher service 100 for determining, in a particular instance,whether the transit route should be adjusted to an alternative stopoption. The ratios of the various stop option weighting factors,relative to one another, may assist in the determination of whichalternative stop option will be served under which traffic conditions.For example, a higher (or lower) weight than the normal stop option maymake it less likely for a stop option to be preferred to the normal stopoption, even under heavily adverse conditions.

FIG. 2A shows an example of a particular stop zone s_(i) and itsassociated stop options, s(i,0 . . . 5). FIG. 2A shows a typicalgrid-like stop zone layout with a normal stop option s_(i,0) and severalalternative stop options on nearby street-corners and blocks. Also shownin FIG. 2A are stop option weighting factors for each of the stopoptions.

Returning to FIG. 1, the data store 105 may also include data, metadata,and/or properties describing a plurality of “route segment options.”Remembering that each express transit line contains a sequence of stopzones, and each stop zone has a variety of stop options, a route segmentoption describes a possible route or path between pairs of stop options.Herein, a set of route segment options for a transit line may be denotedas r(s′,s′)_(j) between pairs of alternative stops s′εA(s_(i)) ands″εA(s_(i+k)), where k≧1. In other words, a route segment optionconnects a given stop option with a subsequent stop option, where thesubsequent stop option is not necessarily in the next stop zone. Routesegment options may be determined, for example, by interaction withexternal trip routing services.

FIG. 2B shows an example of a transit line's stop zones, stop options,and route segment options as a directed, acyclic graph. Stop zones forstops 1, 2, 3, and n are indicated as blue bars. Each stop zone has oneor more stop options (“nodes,” shown as circles), including the “normal”option s(i,0). Each “edge” of the graph (shown as a line) indicates adifferent path from one stop option to another stop option associatedwith a subsequent zone. Stop option weighting factors are also shown foreach stop option.

Returning to FIG. 1, the dispatcher service 100 may read informationpersisted on the data store 105 and in some implementations updateinformation on the data store to update the state of the system.Furthermore, examples of data, metadata, and properties are not intendedto limit the amount or varieties of data that may be stored by the datastore 105. Data store 105 may be implemented as databases, tables, andrecords in a database management system or relational databasemanagement system, examples of which are Microsoft SQL Server® andOracle®. Data store 105 may also be implemented using NoSQL techniques,XML file structures, or other file structures, as will be appreciated bypractitioners in the art.

A transit vehicle location device 110 provides input data that can betransmitted to the dispatcher service to indicate the location of aparticular transit vehicle. A transit vehicle location device 110 caninclude, preferentially, a GPS device placed on a transit vehicle incommunication with the dispatcher service 100. In some implementations,a location device 110 can include specialized transit system cameras,sensors, striker plates, or other devices that detect and identify apresent or passing transit vehicle at a particular location.

A real-time traffic information service (RTIS) 120 provides thecapability to monitor in real-time the traffic and travel conditions ontransit ways such as streets, highways, interstates, roads, and raillines. An RTIS 120 provides data from sensors, cameras, and otherdevices located on a transit way, usually in an interoperable dataexchange format such as DXFS. In some cases, historical and predictivetraffic data may be provided. In some cases, an RTIS 120 may be a thirdparty service, such as Google® Maps, that gathers lower-level data fromother data providers and integrates the data into more comprehensiveservices such as navigation.

A notification interface 130 is a device that displays or broadcastsinformation related to a notification message that some informationupdate about a transit route has occurred. A notification interface 130could be a dynamic sign, such as an LCD or LED display device visible tothe operator and/or to passengers of the particular transit vehicle orof other transit vehicles. A dynamic sign or other type of displaydevice could also be located at a stop option (e.g., on a display screenlocated in a shelter) to tell passengers about transit routes. An audioor tactile representation of the notification message may be broadcast.A notification interface 130 could also be a mobile device application,such as might be operative on an Android® or iOS® device. The mobiledevice application might be provided by a third party and be accessibleto the dispatcher service 100 via an application programming interface(API). In some cases, the mobile device application might be developedin conjunction with the dispatcher service 100 and be made available tointerested patrons. In some cases, a frequent patron may provide his orher mobile number so that the dispatcher service 100 may send thenotification message with an SMS message viewable on the patron's mobilephone, which then becomes the notification interface 130.

In certain embodiments of the subject invention, one or more optionalcomponents 150 may provide additional real-time or historical inputdata. The optional components 150 can be used, for example, to gatherinput that forms part (or all) of a computation of a weighting factor orother dynamically determined factor of the system.

Non-limiting examples of optional components 150 include a system with aclosed-circuit television (CCTV) device and associated image recognitionsoftware 151. Such a system might be used, for instance, to count thepassengers on a transit vehicle or to count the number of passengerswaiting at a transit stop zone or stop option.

In some implementations, a driver may use a mobile device application152 that the dispatcher service 100 can interface with to receive veryaccurate information about passenger or prospective passenger behavior.The mobile app 152 can provide an interface that allows the passenger toassent to tracking location while on the transit system, for example.The dispatcher service can then know the locations of passengers sobetter dynamic route selection can be performed. These features can be,but are not necessarily, part of the same mobile application or suite ofapplications that served as the notification interface 130 for informingthe passenger of transit route changes or updates.

Another type of optional component 150 could include a passengercounting system 153. A passenger counting system 153 may be present, forexample, at the doors of a transit vehicle so that a current ridershipcount is known at all times. The passenger counting system may also bepresent at a stop option, for example at a turnstile on a transitstation shelter. This information may be used to estimate the number ofpassengers that will be inconvenienced by a transit route change, andthus used to adjust dynamic aspects of a weighting factor.

In some cases, an optional component 150 can include a data store ofhistorical data 154. The data in the data store might reflect ahistorical record of real-time data obtained from other optionalcomponents or from other sources. The historical data may be used topredict or estimate, e.g., traffic conditions, traversal times,ridership counts, stop option prospective passenger counts, andpassenger behaviors, among other information. In some cases, historicaldata can include transactional records from prior passenger activities,such as ticket purchases. Any or all of this historical data may be usedto adjust dynamic aspects of a weighting factor or other dynamiccalculations.

FIG. 3 shows an example process flow for dynamic selection of transitroutes. The process flow in FIG. 3 may be implemented, for example, by adispatcher service 100 as described in FIG. 1. Generally, FIG. 3describes a process flow where a transit vehicle provides its currentlocation on a transit line to the dispatcher service, and the dispatcherservice determines a transit route through one or more of the vehicle'sremaining stop zones by choosing an optimized combination of stopoptions and route segment options for that specific transit vehicle.

Processing initiates with the receipt of a dynamic route request from aparticular transit vehicle (300). A dynamic route request serves as anindication to select and/or recalculate the transit route for one ormore remaining stop zones on that particular instance of the transitvehicle's journey. A dynamic route request includes at least the currentlocation of the particular transit vehicle. As noted with respect toFIG. 1, a transit vehicle location device 110, such as a GPS device, mayprovide the current location. The dynamic route request may be sent, forinstance, before the transit vehicle begins a route. The dynamic routerequest may also be sent, for example, when the transit vehicle reachesa stop zone and updates the dispatcher service 100 with its currentlocation; arrival at one stop zone may indicate to the dispatcherservice that computation of a transit route to the remaining stop zonesis needed. In some cases, the current location may be sent periodicallyto the dispatcher service from the transit vehicle location device. Whenthe dispatcher service detects that the current location of theparticular transit vehicle is in proximity of a stop zone, or when thedispatcher service determines that an updated transit route is necessarybased on current traffic conditions, the dispatcher service maydetermine and send an updated transit route to the particular transitvehicle. In some implementations, other input information, such as thecurrent ridership of the transit vehicle, may be sent as part of thedynamic route request.

Knowing the current location of a particular transit vehicle allows thedispatcher service to determine the remaining stop zones, stop optionsfor those remaining stop zones, and the remaining route segment optionsfor those stop options (310). The dispatcher service can determine theremaining route segment options by accessing the data store for thedata, metadata, and properties associated with the transit line. Asnoted with respect to FIG. 2B, for example, a characterization of thepossible route segment options can be understood as a directed, acyclicgraph wherein each edge represents a possible route segment option.

When the remaining route segment options have been enumerated,calculations, determinations, and other operations may be performed withrespect to each individual route segment option (320). Generally, thesecalculations are performed in order to derive a cost function that canbe used to select an optimized transit route.

For each individual route segment, the dispatcher service retrieves,from a real-time traffic information service, one or more trafficcondition factors related to the individual route segment (330). Areal-time traffic information service 120 is described in greater detailin FIG. 1. Since an individual route segment option represents aphysical path from point A to B (where A is a stop option associatedwith one stop zone and B is a stop option associated with a subsequentstop zone on the transit route) through a specific map of streets,highways, byways, trails, etc., the route segment option possessestraffic condition factors that are specific to that particular physicalpath at that particular time. Traffic condition factors can include, butare not limited to, traffic load at the projected time of usage (e.g.,the 5-10 minutes before a busy office building starts work); accidents;special events like lane closures due to construction work, policeoperations, or games/concerts; expected weather at the projected time ofusage; and estimated traversal time from the traffic information servicefor the projected time of usage.

For that individual route segment e, a route segment option weightv(e,t) can be derived from the traffic condition factors at thatspecific time t (340). The route segment option weight is a dynamicweight, determined by the dispatcher service in response to thespecific, time-based, traffic condition factors. The route segmentoption weight can be determined in various ways from the trafficcondition factors. In some cases, for example, the estimated traversaltime of the entire route segment option for the projected time of usagecan be compared to the normal traversal time, which can be an element ofdata/metadata associated with the route segment option descriptionstored in the data store. In some cases, the route segment option weightcan include an estimated susceptibility to disruptions (e.g., accidentsor congestion) during the projected time of usage. In some cases, theroute segment option weight can consider factors such as expectedweather or planned events during the projected time of usage.

A dynamic cost function, c(e,t), can be calculated based on the routesegment option weight and the stop option weighting factors for the pairof stop options connected by the individual route segment (350). Forexample, the dynamic cost function can be calculated by multiplying thedynamic route segment option weight v(e,t) by the average of the stopoption weighting factors for the two connected stop options w(s_(i)) andw(s_(i+k)), where k≧1, as in the Equation:c(e,t)=v(e,t)*(w(s_(i))+w(s_(i+k))/2.

Having computed dynamic cost functions for each individual route segmentfor the remaining stop zones, the particular transit route (for thisparticular transit vehicle at this particular time) through theremaining stop zones can be selected by choosing an optimized set ofroute segment options based on their dynamic cost functions (360).

Choosing the optimized set of route segment options can be accomplishedusing techniques to calculate a path, optimized with respect to thetotality of the dynamic cost functions, through the directed, acyclicgraph representing the remaining stop options and route segment options.This can be performed using well-known path finding algorithms orstandard combinatorial optimization methods, e.g., a Branch-and-Boundsolver, and Mixed Integer Programming and associated refinements. Theoptimized set can also be determined, in some cases, by completeenumeration of the possible combinations and tabulating the sums oftheir dynamic cost functions.

The optimized set of route segment options is equivalent to the bestchoice or routes, based upon traffic condition factors, weightingpreferences, and other information. Under normal conditions, allregular/normal stop options are served, but are connected by dynamicallycalculated route segments. An alternative stop option will be preferredto a regular stop option when this represents an advantage thatameliorates anticipated delays without an excess of inconveniencefactors. The particular transit route selected may then be returned tothe particular transit vehicle (370).

In some embodiments, the dispatcher service may send a notificationmessage to be displayed on an available notification interface 130, asdescribed in FIG. 1. The notification message can include the particulartransit route selected, or one or more aspects thereof, to an operator(e.g., bus driver) of the particular transit vehicles and/or to theoperators of other transit vehicles. The notification message allows theoperator to adjust the path of the transit vehicle to a new or updatedtransit route. The notification message can also communicate suchinformation as stop option, stop zone, and route segment changes topatrons, e.g., passengers riding the transit vehicle or those waitingfor the transit vehicle to arrive at a particular stop option. Thenotification messages may allow the patrons to adjust their schedulesand move to a different stop option from the normal or expected stopoption, etc. Naturally, a notification message could be issued tomultiple notification interfaces simultaneously, in cases where multipleinterfaces are available. The notification message can differ in contentand detail of information, as well as frequency of update, depending onthe notification interface on which it is displayed and for whom thenotification message is intended.

Under some conditions, dynamically selecting route segment options andlocal stop options is not enough to avoid severe transit vehicle delays.Some embodiments include techniques for facilitating the skipping of oneor more stop zones. “Skipping” a stop zone refers to not stopping at anyof the stop options of the stop zone. For example, if a normal transitline's path takes a transit vehicle from stop zone A to stop zone B tostop zone C, each with several stop options, an alternate transit routewhere a stop zone is skipped might notify the transit vehicle to godirectly from stop zone A to stop zone C. Naturally, skipping a stopzone can be disruptive to riding passengers as well as patrons to bepicked up at a stop option.

Embodiments having techniques and systems for determining whether a stopzone should be skipped can include additional weighting factors storedin the data store. In one embodiment supporting skipped stop zones, astop zone (s_(i)) may be skipped when the estimated traversal time forthe best possible set of route segment options from the preceding stopzone s_(i−1) to s_(i) and then on to the next stop zone s_(i+1) isgreater than the originally planned travel time for the same path,multiplied by a weighting factor, y(s_(i))>1. The originally plannedtravel time may be obtained, in some cases, by accessing the data storefor stop zone to stop zone travel time information. The estimatedtraversal time may be computed from information or traffic conditionfactors obtained from a real-time traffic information service.

In an embodiment supporting skipped stop zones, a stop zone (s_(i)) maybe skipped when the estimated traversal time for the best possible setof route segment options from the preceding stop zone s_(i−1) to s_(i)and then on to the next stop zone s_(i+1) is greater than the estimatedtraversal time for the best possible set of route segment optionswithout serving stop s_(i), (s_(i−1), s_(i+1)), multiplied by aweighting factor u(s_(i))>1.

When it is determined that a stop zone should be skipped, estimatedtravel times for route segment options from s_(i−1) to s_(i+1) arecalculated. In some cases, multiple succeeding stop zones may be skippedto find an acceptable transit path. In some cases, no acceptable transitpath is acceptable and the remainder of the trip may be cancelled.

In some implementations, the weighting factors y and u are staticweighting factors. Sometimes, the weighting factors y and u can havedifferent values for each stop zone. In some cases, each of theweighting factors y and u can have a single value for every stop zone inthe transit system or a particular transit line (i.e., there is a singlevalue for y and for u, transit-line-wide or transit-system-wide).

In certain embodiments, a dynamic aspect of a weighting factor, e.g., w,y and u, may be influenced by real-time and/or historical data, and/orpredictions or estimations made from real-time/historical data. In suchembodiments, weighting factors w, y and u may be dynamically computedbased on the dynamic aspect, input data for which may be gathered fromsensors or devices constituting real-time input. In some cases, thesensors or devices may be a type of optional component 150. Sometimes,the real-time input may be received from the dispatcher service asadditional information sent as part of the dynamic route request.

In some cases, the input may be taken from historical data recorded fromsuch real-time sensors or devices. Historical data may be in part formedfrom the real-time data that has been stored in the data store for aperiod of time. In some cases, predictions may be made which are basedon the real-time input and/or historical data.

Some of the data may reflect the behavior of passengers, and some of thepredictions and/or estimations made from historical data may be relatedto passenger activities.

In some cases, the data includes the total number of passengers aboardthe transit vehicle. The number of passengers could be counted, e.g., byan entry/exit door counter, by a device including a camera and patternrecognition software, or by predicting/estimating the information fromcrowd-sourced data.

In some cases, the data includes the number of passengers on the transitvehicle that want to disembark at a certain stop zone. This data mightbe used, for instance, to dynamically, adjust the y or u weightingfactor for a stop zone. This information might be obtained, for example,by information obtained from ticket reading or ticket-purchasingdevices, or by predicting/estimating the information from crowd-sourceddata.

Sometimes, the data includes the number of passengers waiting at aparticular stop option for a transit vehicle to arrive. This data mightbe used, for instance, to dynamically adjust the stop option weightingfactor (w) for the stop option or to influence they or u weightingfactor for a stop zone. The number of passengers waiting could becounted, e.g., by a turnstile counting device attached to the associatedtransit shelter, by a device including a camera and pattern recognitionsoftware, or by predicting/estimating the information from crowd-sourceddata.

In certain cases, the data includes the estimated number of prospectivepassengers heading for a certain transit stop zone or stop option. Thisdata might be used, for instance, to dynamically adjust the stop optionweighting factor (w) for the stop option or to influence the y or uweighting factor for a stop zone. The estimate of prospective passengerscan be determined, e.g., by evaluating behavioral patterns orgeo-location data collected by mobile device applications, obtainingfrom a ticket sales system the number of tickets sold in advance, byevaluating historical data, or by predicting/estimating the informationfrom crowd-sourced data.

Sometimes, the data includes the estimated time passengers will wait ata certain stop option to be collected by a subsequent or succeedingtransit vehicle. This data might be used, for instance, to dynamicallyadjust the y or u weighting factor used to determine whether a stopshould be skipped. The estimated time for a succeeding vehicle may bedetermined, e.g., by interacting with a real-time traffic informationservice.

Understanding of the functioning of certain embodiments of the subjectinvention may be enhanced with the following example, which isillustrative and not intended to be limiting.

In this example, the transit vehicle is an express bus. The express busis assigned to serve a sequence of stops (s₁, s₂, . . . , s_(n)),starting its circulation at 6.00 am. The bus is equipped with a GPSreceiver, a tablet computer installed next to the driver's seat, and acellular two-way connection to a central server where the dispatcherservice and data store reside. As noted, the data store has thepre-computed route segment options and local stop options, and thedispatcher service receives and analyses the bus' GPS data, collectsreal-time traffic information and predicts future traffic conditions,and utilizes all this data to recommend best possible routes to thevehicle.

At 6:00 am the express bus is ready to leave the depot and to executeits first scheduled trip. As no major congestion is predicted over thecourse of the trip, the dispatcher service decides on serving theregular stop options, as scheduled, by utilizing the route segments withthe shortest estimated traversal time.

After leaving the depot, the vehicle proceeds to the first regular Stops₁ and lets passengers board. The dispatcher service recognizes the stopby comparing the bus' assigned sequence of stops with the vehicle's GPSdata. There are four pre-computed route segment alternatives connectings₁ and stop options in A(s₂), which consists of two options. As thereare no current reports about any heavy traffic in the area, the systemdecides to serve the normal stop option, s_(2,0), selects the routesegment option with the shortest expected travel time, and transmits itto the vehicle's computer. It gets displayed to the driver, who thenfollows it.

At 8:30 am, the bus pulls into Stop s_(i). The system recognizes this bycomparing GPS data to the known position of bus stops the vehicle has toserve. The dispatcher service iterates through A(s_(i+1)) and thepre-computed route segment alternatives, and then calculates routesegment option weights and dynamic cost functions according to trafficreports. As most major arteries around s_(i+1,0) are congested byrush-hour traffic, the system elects to serve stop option s_(i+1,2), andchooses a non-obvious route segment which includes a significant detour.This route update is transmitted to the vehicle and displayed to thedriver, who then embarks on the trip. The trip to the next stops_(i+1,2) takes longer than originally scheduled, and alsoinconveniences passengers who plan to embark or disembark at the regularstop. However, it is the most efficient option considering the currenttraffic conditions. Notification messages are sent out for display topassengers of the bus and potential riders.

At 8:45 am, the express bus stops at Stop s_(j). By now the area iscompletely congested due to an accident, and the dispatcher serviceestimates a travel time to the best stop option in A(s_(j+1)) of 45minutes instead of the scheduled 5 minutes, and from there to the bestoption in A (s_(j+2)) of 30 minutes instead of the scheduled 5 minutes.If A(s_(j+1)) were to be skipped, the bus could avoid the congestedarea, and an estimated travel time to A(s_(j+2)) of 15 minutes insteadof the scheduled 10 minutes could be achieved. Based on theseestimations the algorithm decides to skip s_(j+1) and sends the vehicledirectly from s_(j) to A(s_(j+2)). Notification messages are sent outfor display to passengers of the bus and potential riders; the messagesmay include re-routing suggestions and/or instructions for obtainingcompensation.

At 11:00 am, the bus pulls into Stop s_(k), recognized again bycomparing the vehicle's GPS data to the known stop positions. Real-timetraffic information shows no heavy traffic on the shortest route segmentoption to s_(k+1,0), but congestion is foreseen to be developing in tenminutes time. The system therefore selects another route segmentalternative, which includes a slight detour. The route update istransmitted to the on-board computer and displayed to the driver, whocan thus avoid the developing congestion.

FIG. 4 shows a block diagram illustrating components of a computingdevice or system used in some implementations of the describeddispatcher service, data store, notification interface, or mobile app.For example, any computing device operative to run a dispatcher service100, or intermediate devices facilitating interaction between otherdevices in the environment, may each be implemented as described withrespect to system 400, which can itself include one or more computingdevices. The system 400 can include one or more blade server devices,standalone server devices, personal computers, routers, hubs, switches,bridges, firewall devices, intrusion detection devices, mainframecomputers, network-attached storage devices, and other types ofcomputing devices. The hardware can be configured according to anysuitable computer architectures such as a Symmetric Multi-Processing(SMP) architecture or a Non-Uniform Memory Access (NUMA) architecture.

The system 400 can include a processing system 401, which may include aprocessing device such as a central processing unit (CPU) ormicroprocessor and other circuitry that retrieves and executes software402 from storage system 403. Processing system 401 may be implementedwithin a single processing device but may also be distributed acrossmultiple processing devices or sub-systems that cooperate in executingprogram instructions.

Examples of processing system 401 include general purpose centralprocessing units, application specific processors, and logic devices, aswell as any other type of processing device, combinations, or variationsthereof. The one or more processing devices may include multiprocessorsor multi-core processors and may operate according to one or moresuitable instruction sets including, but not limited to, a ReducedInstruction Set Computing (RISC) instruction set, a Complex InstructionSet Computing (CISC) instruction set, or a combination thereof. Incertain embodiments, one or more digital signal processors (DSPs) may beincluded as part of the computer hardware of the system in place of orin addition to a general purpose CPU.

Storage system 403 may comprise any computer readable storage mediareadable by processing system 401 and capable of storing software 402including, e.g., dispatcher service 100, data store 105, instructionsfor a notification interface 130, historical data store 154, and mobileapp 152. Storage system 403 may include volatile and nonvolatile,removable and non-removable media implemented in any method ortechnology for storage of information, such as computer readableinstructions, data structures, program modules, or other data.

Examples of storage media include random access memory (RAM), read onlymemory (ROM), magnetic disks, optical disks, CDs, DVDs, flash memory,solid state memory, phase change memory, or any other suitable storagemedia. Certain implementations may involve either or both virtual memoryand non-virtual memory. In no case do storage media consist of apropagated signal. In addition to storage media, in someimplementations, storage system 403 may also include communication mediaover which software 402 may be communicated internally or externally.

Storage system 403 may be implemented as a single storage device but mayalso be implemented across multiple storage devices or sub-systemsco-located or distributed relative to each other. Storage system 403 mayinclude additional elements, such as a controller, capable ofcommunicating with processing system 401.

Software 402 may be implemented in program instructions and, among otherfunctions, may, when executed by system 400 in general or processingsystem 401 in particular, direct system 400 or processing system 401 tooperate as described herein for enabling dynamic selection of transitroutes. Software 402 may provide program instructions 404 that implementa dispatcher service 100, data store 105, notification interface 130, ormobile app 154. Software 402 may implement on system 400 components,programs, agents, or layers that implement in machine-readableprocessing instructions the methods described herein as performed bydispatcher service 100 (as instructions 404).

Software 402 may also include additional processes, programs, orcomponents, such as operating system software, other applicationsoftware, and software for interfacing with vehicle location devices110, RTIS 120, notification interface 130, CCTV systems 151, mobile apps152, passenger counting system 153, or a historical data store 154.Software 402 may also include firmware or some other form ofmachine-readable processing instructions executable by processing system401.

Dispatcher service 100 may communicate with other devices, externalcomponents, and system components in some cases using an applicationprogramming interface (API). An API is generally a set of programminginstructions and standards for enabling two or more applications tocommunicate with each other. An API is an interface implemented by aprogram code component or hardware component (hereinafter“API-implementing component”) that allows a different program codecomponent or hardware component (hereinafter “API-calling component”) toaccess and use one or more functions, methods, procedures, datastructures, classes, and/or other services provided by theAPI-implementing component. An API can define one or more parametersthat are passed between the API-calling component and theAPI-implementing component. The API and related components may be storedin one or more computer readable storage media. An API is commonlyimplemented as a set of Hypertext Transfer Protocol (HTTP) requestmessages and a specified format or structure for response messagesaccording to a REST (Representational state transfer) or SOAP (SimpleObject Access Protocol) architecture.

In general, software 402 may, when loaded into processing system 401 andexecuted, transform system 400 overall from a general-purpose computingsystem into a special-purpose computing system customized to facilitatedynamic selection of transit routes. Indeed, encoding software 402 onstorage system 403 may transform the physical structure of storagesystem 403. The specific transformation of the physical structure maydepend on various factors in different implementations of thisdescription. Examples of such factors may include, but are not limitedto, the technology used to implement the storage media of storage system403 and whether the computer-storage media are characterized as primaryor secondary storage.

System 400 may represent any computing system on which software 402 maybe staged and from where software 402 may be distributed, transported,downloaded, or otherwise provided to yet another computing system fordeployment and execution, or yet additional distribution.

In embodiments where the system 400 includes multiple computing devices,one or more communications networks may be used to facilitatecommunication among the computing devices. For example, the one or morecommunications networks can include a local, wide area, or ad hocnetwork that facilitates communication among the computing devices. Oneor more direct communication links can be included between the computingdevices. In addition, in some cases, the computing devices can beinstalled at geographically distributed locations. In other cases, themultiple computing devices can be installed at a single geographiclocation, such as a server farm or an office.

A communication interface 405 may be included, providing communicationconnections and devices that allow for communication between system 400and other computing systems (not shown) over a communication network orcollection of networks (not shown) or the air. Examples of connectionsand devices that together allow for inter-system communication mayinclude network interface cards, antennas, power amplifiers, RFcircuitry, transceivers, and other communication circuitry. Theconnections and devices may communicate over communication media toexchange communications with other computing systems or networks ofsystems, such as metal, glass, air, or any other suitable communicationmedia. The aforementioned communication media, network, connections, anddevices are well known and need not be discussed at length here.

It should be noted that many elements of system 400 may be included in asystem-on-a-chip (SoC) device. These elements may include, but are notlimited to, the processing system 401, a communications interface 405,and even elements of the storage system 403 and software 402.

Alternatively, or in addition, the functionality, methods and processesdescribed herein can be implemented, at least in part, by one or morehardware modules (or logic components). For example, the hardwaremodules can include, but are not limited to, application-specificintegrated circuit (ASIC) chips, field programmable gate arrays (FPGAs),system-on-a-chip (SoC) systems, complex programmable logic devices(CPLDs) and other programmable logic devices now known or laterdeveloped. When the hardware modules are activated, the hardware modulesperform the functionality, methods and processes included within thehardware modules.

It should be understood that the examples and embodiments describedherein are for illustrative purposes only and that various modificationsor changes in light thereof will be suggested to persons skilled in theart and are to be included within the spirit and purview of thisapplication.

Although the subject matter has been described in language specific tostructural features and/or acts, it is to be understood that the subjectmatter defined in the appended claims is not necessarily limited to thespecific features or acts described above. Rather, the specific featuresand acts described above are disclosed as examples of implementing theclaims and other equivalent features and acts are intended to be withinthe scope of the claims.

What is claimed is:
 1. A system for dynamic selection of transit routes,the system comprising: one or more computer readable storage media; adata store contained on the one or more computer readable storage mediacomprising one or more data structures related to: one or more transitlines in a transit system; a plurality of stop zones served by each ofthe one or more transit lines; one or more stop options associated witheach of the plurality of stop zones; a plurality of stop optionweighting factors, wherein each stop option weighting factor describes arelative desirability of a particular stop option in accordance with oneor more preference criteria; a plurality of route segment options,wherein each route segment option describes a path between a first stopoption and a subsequent stop option; and program instructions for adispatching service stored on the one or more computer readable storagemedia that, when executed by a processing system, direct the processingsystem to: in response to receiving a dynamic route request, wherein thedynamic route request comprises a current location of a particulartransit vehicle on a particular transit line, wherein the currentlocation is obtained from a transit vehicle location device, determine aparticular transit route from the current location of the particulartransit vehicle through one or more remaining stop zones of theparticular transit line by: determining one or more remaining routesegment options based on the one or more remaining stop zones and theplurality of route segment options in the data store; for eachindividual route segment of the one or more remaining route segmentoptions: retrieve, from a real-time traffic information service, one ormore traffic condition factors related to the individual route segment;determine, from the one or more traffic condition factors, a routesegment option weight; calculate a dynamic cost function based on theroute segment option weight for the individual route segment, andparticular stop option weighting factors for the stop options connectedby the individual route segment; and selecting the particular transitroute, wherein the particular transit route is comprised of an optimizedset of individual route segments, wherein the optimized set ofindividual route segments is optimized with respect to a totality ofdynamic cost functions; and returning the particular transit route tothe particular transit vehicle.
 2. The system of claim 1, whereinselecting the particular transit route comprises: determining anestimated traversal time for a best possible set of route segmentoptions from a preceding stop zone (s_(i−1)) to a specific stop zone(s_(i)) and on to a next stop zone (s_(i+1)); and when the estimatedtraversal time is greater than an originally planned traversal timebetween s_(i−1) and s_(i+1) multiplied by a selected first skipweighting factor, wherein the selected first skip weighting factor isgreater than one, determining the optimized set of individual routesegments by skipping the specific stop zone sand proceeding directlyfrom s_(i−1) to s_(i+1).
 3. The system of claim 2, wherein the datastore further comprises one or more properties related a plurality offirst skip weighting factors, wherein each of the plurality of firstskip weighting factors relates to an associated stop zone, wherein theselected first skip weighting factor is the one of the plurality offirst skip weighting factors associated with the specific stop zone. 4.The system of claim 1, wherein selecting the particular transit routecomprises: determining a first estimated traversal time for the bestpossible set of route segment options from a preceding stop zone(s_(i−1)) to a specific stop zone (s_(i)) and on to a next stop zone(s_(i+1)); and when the first estimated traversal time is greater than asecond estimated traversal time for the best possible set of routesegment options between the preceding stop zone (s_(i−1)) and the nextstop zone (s_(i+1)) multiplied by a selected second skip weightingfactor, wherein the selected second skip weighting factor is greaterthan one, determining the optimized set of individual route segments byskipping the specific stop zone s_(i) and proceeding directly froms_(i−1) to s_(i+1).
 5. The system of claim 4, wherein the data storefurther comprises one or more properties related a plurality of secondskip weighting factors, wherein each of the plurality of second skipweighting factors relates to an associated stop zone, wherein theselected second skip weighting factor is the one of the plurality ofsecond skip weighting factors associated with the specific stop zone. 6.The system of claim 1, further comprising program instructions that,when executed by the processing system, direct the processing system to:send one or more notification messages to one or more notificationinterfaces.
 7. The system of claim 6, wherein the one or morenotification messages comprise information describing one or more of:the particular transit route; a delay in arrival time at a stop zone; achange in a selected stop option; and a selected route segment option.8. The system of claim 1, wherein a dynamic aspect of a weighting factorcomprises one or more of: a first count of passengers on the particulartransit vehicle; a second count of passengers who are planning todisembark at a given stop zone; a third count of passengers waiting at aparticular stop option for the particular transit vehicle to arrive; anestimated number of prospective passengers heading for a certain stopzone or stop option; and an estimated wait time passengers will wait ata certain stop option to be collected by a subsequent transit vehicle.9. The system of claim 8, wherein an input to the dynamic aspect isobtained in real-time from the real-time traffic information service, anoptional component, or estimated from historical data.
 10. The system ofclaim 1, wherein the one or more preference criteria of a stop optionweighting factor comprise one or more of: a walking distance from anassociated stop option to a normal stop option; an available pedestrianaccess from the normal stop option to the associated stop option; and aquality of facilities at the associated stop option.
 11. The system ofclaim 1, wherein the route segment option weight is computed from inputdata, wherein the input data relates to the individual route segment fora projected time of usage, the input data comprising one or more of: anestimated traversal time; an estimated susceptibility to disruptions; atraffic load; a current or predicted delay; a special event; and aweather forecast.
 12. A method for dynamic selection of transit routes,the method comprising: receiving a dynamic route request, wherein thedynamic route request comprises a current location of a particulartransit vehicle on a particular transit line, wherein the currentlocation is obtained from a transit vehicle location device; determininga particular transit route from the current location of the particulartransit vehicle through one or more remaining stop zones of theparticular transit line by: determining one or more remaining routesegment options based on the one or more remaining stop zones and aplurality of route segment options; for each individual route segment ofthe one or more remaining route segment options: retrieve, from areal-time traffic information service, one or more traffic conditionfactors related to the individual route segment; determine, from the oneor more traffic condition factors, a route segment option weight;calculate a dynamic cost function based on: the route segment optionweight for the individual route segment, and stop option weightingfactors for stop options connected by the individual route segment; andselecting the particular transit route, wherein the particular transitroute is comprised of an optimized set of individual route segments,wherein the optimized set of individual route segments is optimized withrespect to a totality of dynamic cost functions; and returning theparticular transit route to the particular transit vehicle.
 13. Themethod of claim 12, wherein selecting the particular transit routecomprises: determining an estimated traversal time for a best possibleset of route segment options from a preceding stop zone (s_(i−1)) to aspecific stop zone (s_(i)) and on to a next stop zone (s_(i+1)); andwhen the estimated traversal time is greater than an originally plannedtraversal time between s_(i−1) and s_(i+1) multiplied by a selectedfirst skip weighting factor, wherein the selected first skip weightingfactor is greater than one, determining the optimized set of individualroute segments by skipping the specific stop zone s_(i) and proceedingdirectly from s_(i−1) to s_(i+1).
 14. The method of claim 12, whereinselecting the particular transit route comprises: determining a firstestimated traversal time for the best possible set of route segmentoptions from a preceding stop zone (s_(i−1)) to a specific stop zone(s_(i)) and on to a next stop zone (s_(i+1)); and when the firstestimated traversal time is greater than a second estimated traversaltime for the best possible set of route segment options between thepreceding stop zone (s_(i−1)) and the next stop zone (s_(i+1))multiplied by a selected second skip weighting factor, wherein theselected second skip weighting factor is greater than one, determiningthe optimized set of individual route segments by skipping the specificstop zone s_(i) and proceeding directly from s_(i−1) to s_(i+1).
 15. Themethod of claim 12, further comprising: sending one or more notificationmessages to one or more notification interfaces.
 16. The method of claim15, wherein the one or more notification messages comprise informationdescribing one or more of: the particular transit route; a delay inarrival time at a stop zone; a change in a selected stop option; and aselected route segment option.
 17. The method of claim 12, wherein adynamic aspect of a weighting factor comprises one or more of: a firstcount of passengers on the particular transit vehicle; a second count ofpassengers who are planning to disembark at a given stop zone; a thirdcount of passengers waiting at a particular stop option for theparticular transit vehicle to arrive; an estimated number of prospectivepassengers heading for a certain stop zone or stop option; and anestimated wait time passengers will wait at a certain stop option to becollected by a subsequent transit vehicle.
 18. The method of claim 17,wherein an input to the dynamic aspect is obtained in real-time from thereal-time traffic information service, an optional component, orestimated from historical data.
 19. The method of claim 12, wherein astop option weighting factor comprises one or more preference criteriaselected from the group consisting of: a walking distance from anassociated stop option to a normal stop option; an available pedestrianaccess from the normal stop option to the associated stop option; and aquality of facilities at the associated stop option.
 20. The method ofclaim 12, wherein the route segment option weight is computed from inputdata, wherein the input data relates to the individual route segment fora projected time of usage, the input data comprising one or more of: anestimated traversal time; an estimated susceptibility to disruptions; atraffic load; a current or predicted delay; a special event; and aweather forecast.